…t for custom element tags.
This changeset includes a major iteration on the regular expression used to balance tags, with comprehensive test coverage to ensure that all scenarios are supported or unsupported as expected.
Props dmsnell, westonruter, birgire.
Fixes #47014.
git-svn-id: https://develop.svn.wordpress.org/trunk@45929 602fd350-edb4-49c9-b593-d223f7449a82